Mineral oil composition containing a polymericalkyl metaphosphimate



Patented Jan. I, 1952 MINERAL OIL Coll/[POSITION CONTAIN ING A POLYMERICALKYL METAPHOS- PHIMATE Ferdinand P. Otto, Woodbury, and Robert w.

Barrett, Sewell, N. J., assignors to Socony- Vacuum Oil Company, Incorporated, a corporation of New York No Drawing. Application November 14, 1949, Serial No. 127,268

, 4 Claims. (Cl. 252-493) This invention relates generally to improved lubricating oil compositions and more particularly to lubricating oil compositions having advantageously low pour points.

As is well known, mineral lubricating oils, particularly those derived from paraffin base crudes, tend to congeal and become non-flowing at temperatures slightly below normal atmospheric temperatures. This is due to the crystallization of the wax content of the oil and, of course, is undesirable, particularly if the oil is to be utilized in automotive engines in temperate climates where temperatures normally encountered in winter cause the oil to congeal in the crankcase when the engine is idle. As a result, when the engine is started cold, it is subjected to conditions of increased wear and breakdown, since the parts do not receive proper lubrication. It is known, however, that this condition may be counteracted by adding to the oil small amounts of certain chemical compounds which inhibit the crystallization of the wax content therein and thus efiect a considerable lowering of the temperature at which the oil will cease to flow. Such compounds are known as pour point depressants. The present invention is concerned with oil compositions containing additive compounds of this type.

We have found that when a minor proportion of a polymer product obtained by first condensing a phosphonitrilic halide with an alcohol selected from the class consisting of n-tetradecanol and a mixture of primary, normal, saturated, aliphatic alcohols having an average of about 14 carbon atoms per molecule and then subjecting the condensation product so produced to polymerizing conditions, is added toa mineral lubricating oil, the pour point of the oil is lowered to a considerable extent.

It is, therefore, an object of this invention to provide mineral lubricating oil compositions of lowered pour point, said compositions containing small amounts of the aforesaid type of polymer product. Other objects will appearfrom the following detailed description of the invention.

The condensation products which are polymerized to produce the oil addition agents contemplated herein are alkyl metaphosphimates. It has been known heretofore that these materials could be polymerized. Thus, Patent No. 2,214,769 describes the polymerization of similar compounds obtained by the condensation of phosphonitrilic halides with organic compounds such as methyl, ethyl, propyl, butyl and amyl a1- cohols. No mention ismade in that patent.

however, of the particular polymerization products herein contemplated, viz. those obtained by polymerizing an alkyl metaphosphimate derived from a primary, normal saturated alcohol having 14 carbon atoms or from a mixture of primary, normal, saturated alcohols having an average of approximately 14 carbon atoms per molecule; nor does the patent suggest the utility of such'polymers as pour point depressants in mineral oils.

Another patent, No. 2,109,491, describes lubricating oil compositions containing condensation products of metaphosphimates obtained. from certain other aliphatic alcohols, including lauryl, dodecyl and oleyl alcohols. However, no mention is made of metaphosphimates produced from the alcohols useful in this invention, viz. n-tetradecanol, or a mixture of primary, normal, saturated alcohols having an average of 14 carbon atoms per molecule. Furthermore, there is no disclosure to the effect that when the latter compounds are subjected to polymerizing conditions as hereinafter defined, reaction products are obtained which are effective as pour point depressants in mineral lubricating oils.

As indicated hereinbefore, in accordance with this invention, a phosphonitrilic halide, particularly a phosphonitrilic chloride, comprised substantially of (PNC12): and (PNClzM, is first condensed with either n-tetradecyl alcohol, or of a mixture of primary, normal, saturated alcohols having an average of about 14 carbon atoms per molecule at a relatively low temperature, 1. e. not over about C., to form a condensation product. The condensation reaction is more efl'icient if the alcohol is first converted to a metal alcoholate of a metal such as sodium or potassium. The condensation reaction, when employing (PNC12)3 and sodium tetradecanolate, for example, is represented by the following equation:

At the aforesaid condensation temperature, substantially no polymerization of the 'phosphonititrilic chloride will occur. The condensation product is then polymerized by heating at higher temperatures, for example, from about 200 C. up to about 400 C., or by further heating at the lower temperatures in the presence of a suitable polymerization catalyst, such as .AlCls, ZnCls, BF: and the like. We have found it convenient to carry out the reaction in the presence of about 5 per cent by weight of AIClz, using xylene as a solvent and maintaining the temperature at the reflux temperature of the solvent.

Although the phosphonitrlllc chlorides are per-- Per cent C10: 2.5 C12=55.0 C1-r=20.5 C16: 9.0

C1a=13.0 7 Ave. No. C Atoms=13.5

The following examples and results of tests will serve to illustrate more fully the principles of our invention.

PREPARATION OF PHOSPHONITRILIC CHLORIDE Reaction mixture:

Ammonium chloride grams 130 Phosphorus pentachloride do 400 Symmetrical tetrachloroethane cc 1000 Procedure.The reactants and solvent were placed in a 3-neck round bottom flask equipped with a reflux condenser, thermometer and mechanically driven stirrer. The resulting mixture was refluxed at 136 C. to 142 C. for a period of 7 hours. After cooling, the mixture was filtered to remove excess ammonium chloride, and the filtrate topped to 55 C. at 11 mm. pressure to remove 850 cc. of tetrachloroethane. On cooling the residue in an ice-salt bath, the product consisting of essentially (PNC12)3 and (PNC12)4 crystallized from the mixture and was filtered therefrom. After washing with cold tetrachloroethane, the material contained on the filter weighed 8'7 grams and by analysis contained 12.1 per cent nitrogen (theor.= 12.0

EXAMPLE I Reaction product of phosphonitrilic chloride with Sodium "LoroZ-B alcoholate Reaction mixture:

Metallic sodium grams 5.0 Butanol 'cc 1'00 Lorol-B grams 47.0 Phosphonitrilic chloride do 116 Xylene cc 100 Procedure-Metallic sodium was added to the butyl alcohol contained in a round bottom flask equipped with a thermometer, reflux condenser "made acidic with dilute H01 and then water washed until neutral. The solvent Was then removed from the product by distillation to a temperature of 175 C. at '5 mm. TheLorol--B 4 metaphosphimate so obtained contained 6.58% phosphorus (theor.=6.1%) and 2.97% nitrogen (theor.=3.0%).

EXAMPLE I-A Poly Lorol-B M etaphosphimate Reaction mixture:

Lorol-B metaphosphimate grams 18.0

(Example I) Anhydrous aluminum chloride do 0.9 Xylene cc 50 Procedure-The above mixture was placed in a 3-neck round bottom flask equipped with a reflux condenser, thermometer and mechanically driven stirrer. After heating for a period of 9 hours at 125 C. the reaction product was washed with water until the washings were neutral. This was followed by topping to 175 C. at mm. to remove the solvent and obtain the 'finished product, a semi-viscous yellow oil.

The procedures for preparing the following products were essentially the same as those described in Examples I and I-A.

EXAMPLE II Didecyl M etaphosphimate Reaction mixture:

Metallic sodium grams 5.0 n-Butyl alcohol cc 100 l-decanol grams 60 Xylene cc 100 Phosphonitrilic chloride "grams" 11.6

EXAMPLE II-A Poly decyl metaphosphimate Reaction mixture:

iDecyl metaphosphimate.1 ;grams 16.0

(Example II) Anhydrous aluminum chloride do 0.8 Xylene cc.. 150

EXAMPLE III Dodecyl metaphosphimate Reactionmixture:

Metallic sodium grams 5.0 Butanol 'cc 100 'l-dodecanol -grams 40 Xylene cc 100 Phosphonitrilic chloride -grams "11.6

"EXAMPLE III-A Poly dodecyl metaphosphimate Reaction mixture 'Dodecyl metaphosphima'te 'grams 16.0

"(Example II'I) Anhydrous aluminum chloride do 028 Xylene 'cc 100 -EXAMPLE IV Tetradecyl metaphosp'himate Reaction mixture:

Reaction mixture:

Te'tradecyl metaphosphimate v grams 16.0

(Example IV) Anhydrous aluminum chloride do Xylene cc..-

EXAMPLE V Hexadecyl metaphosphimate Reaction mixture:

Metallic sodium grams 5.0 Butanol cc 150 l-hexadecanol grams 53 Xylene cc- 100 Phosphonitrilic chloride grams 11.6

EXAMPLE V-A Poly hexadecyl metaphosphimate Reaction mixture:

Hexadecyl metaphosphimate grams 16.0

(Example V) Reaction mixture:

Octadecyl metaphosphimate grams 20.0

(Example VI) Anhydrous aluminum chloride do 0.9 Xylene cc 50 POUR POINT DEPRESSION In order to demonstrate the effectiveness of the particular group of polymer products contemplated by this invention as pour point depressants for mineral lubricating oils, the various products prepared as described in the foregoing examples were blended, in minor proportions, with a. typical lubricating oil and the blends subjected to tests to ascertain the pour points thereof. The oil used in all of these blends was a solvent-refined Mid-continent SAE 30 grade stock having an initial pour point of 20 F. and a kinematic viscosity at 210 F. of 11.96. The

Table it shows the results obtained with blends of a number of monomeric alkyl metaphosphimates produced by merely condensing phosphonitrilic chloride (consisting substantially of (PNC12)3 and (PNClzM) with various primary, normal, saturated, aliphatic alcohols containing from 10 to 18 carbon atoms including a product obtained from a mixture of primary, normal,

saturated, aliphatic alcohols having an average of about 14 carbon atoms per molecule, i. e. Lorol-B. It will be seen from the data that none of these provide any significant pour point depressant effect.

Table II shows the results obtained with oil blends of the polymerized products shown in Table I. It will be seen that only the monomeric products prepared from n-tetradecanol and the Lorol-B alcohol mixture provide polymerized products which are significantly effective pour point depressants.

The amount of the polymeric alkyl metaphosphimate product to be added to the mineral lubricating oil will vary somewhat with the intended application of the oil composition, but generally will range from about .1 per cent to about 10 per cent. However, significant improvement may be obtained with lesser amounts. It is also contemplated that the product compounds be incorporated in the oil in greater amounts, i. e. above 10%, to provide concentrates for marketing. These concentrated compositions have the advantage of affordingv a readily soluble form of the additive compound for dilution with additional quantities of oil prior to actual use.

The oils in which our new addition agents are used, or the oil concentrates, may also contain other additives, designed to improve the character of the oil in other respects, such as detergency, V. I. antioxidant quality, etc.

Having now fully described our invention what we wish to claim as new and patentable is:

1. A mineral lubricating oil containing a minor proportion, sufficient to depress the pour point thereof, of a polymeric n-tetradecyl metaphosphimate product obtained by (1) reacting a phosphonitrillic halide with n-tetradecanol at a temperature not in excess of about 150 C. to form n-tetradecyl metaphosphimate and (2) subjecting the metaphosphimate to polymerization by t su s are Presented in ab I and III the method selected from (a) further heating the Table I ASIM Pour Point Ex. No. Reaction Product (PNGlz)x+2 "Lorol-B) ONa +15 (PNCh)z+2 m nONa +20 +25 Table II R H P d tPl ma ASTM Pour Point eac 011 1'0 oyme 8 with A101:

I- (PNGlz):+2(Lorol-IB")ONa -s0 -a0 -a0 -10 IPA... PNou),+2owHmoNa +15 +15 III-A. (PNO1z)=+2CmHz5ONa +15 +20 IVA (PNGlQ),+2CuHnONa- -25 -20 -15 -5 VA PNo12),+2ouHaoNa +20 +15 VIA (PNClz)z+2C1sHnONa +15 +15 17 :metaphosphimate :product at :a temperature not inexcess .of.150'C. in the presence of apolymer- -ization catalyst, and (b) heating the .metaphos- .phimate'product at :a temperature ranging from about 200 .C. to about 400 C.

2. A mineral lubricating .011 containing aminor proportion, sufiicient to depress the pour point thereof, of a polymeric n-tetradecyl metaphos- .phimate product obtained by reacting phosphonitrillic chloride With :n-tetradecanol at a temperaturetnot in excess ofabout 150" C. to form an :n-tetradecyl metaphosphimate :and then subjecting the metaphosphimate .to polymerization -iby the'method selected "from (a) further heating the .metaphosphimate .at a temperature not in :excess of 150 C. in the presence of an aluminum chloride catalyst,'and (b) heating the metaphos- 'phimate at a temperature ranging from about "200 C. to about 400 C.

3. A mineral lubricating oil containing a minor proportion, sufficient to :depress the pour point thereof, of a polymeric alkyl metaphosphimate product produced by (1) reacting a phospho- 'nitrillic halide with a mixture of primary; normal, saturated alcohols, said mixture consisting of alcohols containing from to 18 carbon atoms :in thefollowing approximate proportions Per cent C10 2.5 C12=55.0 C14=20.5 C1e= 9.0 and C1a=13.0

to form an alkyl metaphosphimate and (2) subjecting the metaphosphimate to polymerization by themethod selected from (a) further heating the metaphosphimate product at a temperature Per cent 7 C10: 2.5 C12=550 C14=20.5 C16: 9.0 and C1s=13.0

to form an alkyl metaphosphimate and (2) subjecting the metaphosphimate to polymerization by the method selected from (a) further heating the metaphosphimate product at a temperature not in excess of C. in the presence of an aluminum chloride catalyst, and (b) heating the metaphosphimate product at a temperatre ranging from about 200 C. to about 400 C.

FERDINAND P. OTTO. ROBERT .BARRETT.

REFERENCES CIT-ED The following references are .of record in the .file of this patent:

UNITED STATES. PATENTS Name, Date Lipkin Mar. 1, 1938 Number 

1. A MINERAL LUBRICATING OIL CONTAINING A MINOR PROPORTION, SUFFICIENT TO DEPRESS THE POUR POINT THEREOF, OF A POLYMERIC N-TETRADECYL METAPHOSPHIMATE PRODUCT OBTAINED BY (1) REACTING A PHOSPHONITRILLIC HALIDE WITH N-TETRADECANOL AT A TEMPERATURE NOT IN EXCESS OF ABOUT 150* C. TO FORM N-TETRADECYL METAPHOSPHIMATE AND (2) SUBJECTING THE METAPHOSPHIMATE TO POLYMERIZATION BY THE METHOD SELECTED FROM (A) FURTHER HEATING THE METAPHOSPHIMATE PRODUCT AT A TEMPERATURE NOT IN EXCESS OF 150* C. IN THE PRESENCE OF A POLYMER IZATION CATALYST, AND (B) HEATING THE METAPHOSPHIMATE PRODUCT AT A TEMPERATURE RANGING FROM ABOUT 200* C. TO ABOUT 400* C. 